Telephone system



Aug. 3 1926.

Y 1,594,432 J. F. TOOME Y TELEPHONE SYSTEM Filed Fe'b. 2s, 1924 2 Sheets-Sheet 2 4 Tip lnvenfar L/am Tap/nay Patented Aug 3, 1926.

urn res JOHN F. TOOMEY, GENE'W YORK, N. Y., ASSIGNGR 'I'O A1iZIERIGAN AND assists TELEGRAPH oorvrraivr, a con'sona'rioiv orn'nwYon-Ie TELEPHONE SYSTEM.

Application, fi1ed-February 28 19 24 a cope-riding application ,of L. A.

impulses .andringing-and supervisory sige hilorti ne'r, Serial NoQ 667,?88, tiled October 11, 192$,there is shown a syr renipt the above type wherein a composite leg ofa toll line is employedtor the transmission of dial nals vbetween a machine switching operatorsposition and a machine switching subscribers line. In thiscopending application, interrupted direct current is transmitted over the composite leg to effect the ringing of avvante d subscriber.

An object of this invention is to improve systems of the type disclosed the above mentionedcopending application by substituting an arrangement whereby a low the rpiency alternating current may he applied tirectly to a composite leg of atoll line for ringing purposes, in place of the rather er:-

pensive equipment commonly used whereby the low frequency alternating current has to be translated into a high frequency current suitable for transmission over the line to effect the ringing; By this invention the ordinary w t'requenoy ringing current source common in standard cord circuits may be used to effect the ringing operations at the distant end of toll circuit.

Another object is to combine in greatly simplified cord and toll line circuits such a ringing arrangement With means for transmitting dialing impulses and supervisory signals over a composite leg of a toll line. This circuit involves a minimum amount of apparatus and operatesin a reliable and etfici-ent manner to produce a number of easily identified supervisory signal indications.

Another object is the provision in a toll line circuit of this type whereby the dialing impulses received from the cord circuit are transmitted directly over the composite leg oi the toll line thus;eliminating pulsing relay or other impulse repeating means "c'omr i contactsot p-lugcEL-O-and jaclr' ll, high 'r sistance Winding ot relay'l-dand otmarginal.relay lfi to ground. llhe o1 1 tion er relay 161 performs no useful; function e at this time Qvvhile the operation of rel ayil? monly employed incircuits of thistype.

it is believed that aclear understanding oi the invention will be had trom': the fol "lowing description'made with reference-to the accompanying drawing in \vhic'lriFigure 1' time diagrammatically subscriber s line A [nd a por-tionfot a .toll l' n'e operi The circuits and equfpmen Serial No. 635,775.

ators cord circuit C equipped; for transmitt ng supervisory signals, dialing impulses and A, C. signaling current over a coinposited toll line L, the outgoing end oi which is shown in thisfigure. Fig. the incoming end ofthe composited L terminating inajack at the incoming; toll shows toll line operators position G, and equipment 'LF shown in j a line iinder agra-n'imatically. t employed; in the establishment of aiconnection from the line finderLF to a machine switching: subscriber B are also indicated diagrammatically; at

5D to indicate the automatic switches involved in the connection,,a nd atS to indicate a, sender equipment such as is used for the reception ot' impulses-andyfor the control of. the setting up'of a connection-as is -Welluknovvn in the ,art. As this, por ion Oil the circuit terms no part of the invention reference may be had, for, a -tuller disclosure thereof, to the above mentioned coi aendino a lication.

The invention Willbe described in connection With this disclosure; first, by describing the operation when the composite toll line is employedtor a regular ring down operation, that'is, when it is used to extend a connection to a manual operatorgand second, by describing the operationiwhen the toll line is employed tore tending-a connection to a machine switching subscriber.

When the composite tollline isto-be employed for regular; ring down operation, that is, in this case for Xtending a connection between a subscriber at Ato the toll operators position C at oneexchange and the in coming toll operators position C at another exchange, the procedure is as Ti'ollows: After a connection has been established from the calling subscriber A to-the'toll opconnects the ring; conductor, #trom, the alternatinglcurrent ringing souiqoe A1 aat tit) spring 42 of ringing key to the composite leg of toll line L, at its inner lower armature and front contact. This applica tion of ringing current 15 causes the alternating current relay 118 at the distant exchange to operate over the following circuit from the ringing source through the above mentioned contact of relay 17, thecomposite leg 22 of toll line L, lower armature and back contact of relay 117, winding of alternating current relay 118, condenser 120 to ground. The operation of alternating current relay 118 breaks the obvious circuit for relay 122 and the release of this relay causes a circuit for relay 123 to be closed from battery, winding'of relay 123, armature and back contact of relay 12 i, armature and back contact of relay 122 to ground. The operation of relay 123 closes an obvious circuit for the line lampv 125 which lights and notifies'the tolloperator at C that a manualconnection is wanted and the operator G thereupon extends the connection in the usual manner.

In a similar manner the incoming calls to the toll operator C from the toll operator C causes the operation of the alternating current relay 18 which releases relay and operates relay 33 thus lighting the line lamp and notifying the operator C that a manual connection accessible from this exchange is wanted. It is apparent from this disclosure that the outgoing and incoming ends of the toll line L may be identical, that is, as far as the: equipment for ex-' tending calls manually in either direction is concerned and that the ordinary low frequency ringing current source, such as 4:1 of a standard cord circuit, may be employed to affect the ringing operations.

The following description u ill be directed to the establishment of a connection over the composite toll line from a manual subscriber A to a machine switching subscriber B over the line finder indicated st ll-F and and the intermediate automatic switches D.

Assuming, as in the regular ring down operations of the system, that the subscriber A has been connected t-othe toll operators cord circuit C and the operator at this position has received the number of the, wanted subscriber B, the operator at C will, after having inserted plug 10 in jack 11, operate dialing key 12. The following circuit is thereby established from a high voltage bat tery now connected to the spring 13 of the dialing key 12, normal contact at spring 14 of ringing key 15, sleevecontacts of plug 10 and jack 11. high resistance winding of relay 16, winding of relay 17 toground;

This circuit operates relays 16 and 17 and .as other contacts of the dialing key 12 have connected the dialing circuit through the pulsing contacts of dial 20 and through the winding of polarized.winding 41', the opera 43 of dialing key 12,winding of polarized relay 11', pulsing contacts of dial 20,,operated contact at spring 45 of dialing key 12, normal contact at spring l6 of ringingkey 15, tip contacts of plug 10 and jack 11, upper armature and front contact of relay 17 to ground. It will be noted that this circuit is a direct pulsing circuit through the dial contacts 40, and not repeated or relayed 111 the toll circuit, but extended over'the composite leg 22 directly to the pulsing relay 200. Pulsing relay 200 is therefore operated immediately upon closing up this circuit and, as shown in the above mentioned copending application, the line finder LP is thereby caused to connect withan idle district switch and a district sender equipment, such as S this equipment being shown merely in diagrammatic form as it does not form part of this invention. The details indicated are thought to be sufficiently clear for the explanation of the functions of the pulsing circuit as above traced. It should be noted that the direction of the current in this circuit is such as not to operate the pulsing relay 4-1 and that'when the sender S has been found, relay 300 thereof is operated causing relay 301 to be operated through intermediate equipment (not shown) which in turn causes a dialing signal to be given to the operator at C in the following manner:

Relay 301 through intermediate equipment operation of relay 11 will therefore close a circuit for SUPGEVlSOlY lamp 50 as follows: from battery, lamp 50, operated contact at spring 51 of dialing key 12, armature and front conta tof polarized relay 11, lefthand armature and back contact of relay 52, interrupter 53 to ground. The circuit through supervisory lamp 50 will therefore beinterrupted and the lamp alternately lighted and extinguished to indicate to the operator C that she may proceed to dial.

in respon e to this flashing of lamp 50, the

;. operator at G actuates the dial 20, and upon contacts 111 accordance with the wanted subscribers number intermittently interrupts the pulsing circuit previously traced and thus intermittently releases and operates the pulsing relay 200 which now, in accordance with the description in the above mentioned copending application, causes corresponding operations of relay 300. The-manipulation of relay 800 thereupon effects the setting of theautomatic switches D in well known manner and when all digits have been dialed the line of the wantedsubscriber B is connected through these automatic switches .L) to equipment in the line finder LF that thereby causes the operation of relay 202. It

should be noted that this relay 202 was re leased during the operation of the setting up of the wanted subscribers number in the sender S. The operation of relay 202 at this time, as before, substitutes the positive pole of battery 203 for the negative pole of battery 201 in the dialing circuit and as relay 56 is now released due to the oft-normal contact 55 being open, this reversal of the current in the dialing circuit will operate the polarized relay 41' and cause the lamp 550 to be lighted. In this instance the lamp will glow with p a steady light as relay 52 when first energized by the closing of off-normal contact established a locking circuit for itself from battery, right-hand winding of relay 52, right-hand armature and front contact through the operated contact of spring 61 to ground. The circuit for the line lamp 50 is thereby switched from the interrupter 52 to a ground at the left-hand armature and front contact of relay 52. The steady glow of lamp 50 notifies the operator at C that the wanted subscribers line has been reached. The operator at C now restores the dialing key 12, and thereby releases relay 52, opens the circuit for lamp 50 and disconnects the dialing circuit at springs l3 and 45. The restoring of dialing key 12 to normal does not, however, extinguish the lamp 50 which is maintained lighted by the following circuit from battery, supervisory lamp 50, normal contact of spring 13 of key 12, sleeve contacts of plug 10and jack 11, low resistance winding of relay 16, armature and front contact of polarized relay to ground. It should be noted that the above circuit is ,established directly as a result of thelrestoration of key 12 as when the high voltage battery at the spring 13 is removed relay" 17 is released thus establishinga circuit over the compos te leg through the lower armature and back contact of relay 17, winding of polarized relay 60, right-hand armature and front contact of relay 16 to battery. Relay, 16 being comparatively sluggish so as to permit this circuit to be closed and thus. allow relay 60 to operate frombattery'at relay 202. The operation of relay 60.thus provides. a ground for maintaining relay 16 operated and lamp 50 to be lighted. It should be mentioned that relay 17is not again energized by the battery at lamp 50 as it is marginal in its operation and the current in this instance is not suflicient to cause its operation. i

*When the subscriber at B is automatically signaled in any well known manner and re- ,moves his receiver from the hook, the circuit for relay 202 is opened and the relay is: released, whereupon the negative pole of battery 201 is substituted for thepositive pole of battery 203 causing the current over the composited leg to reverse and polarized relay 60 to release. The ground at the armature and front contact of relay 60 is therefore removed causing the circuit for maintaining relay 16 energized to extend through the high resistance winding of relay 16 and winding of relay 17 to ground. This circuit does not permit sufficient current to pass to maintain lamp 50 lighted. Lamp 50, there fore, by being extinguished at this time, indicates to the operator at C that the subscriber at B has answered the call. Conversation may now take place as a talking circuit over the toll line is established tothe called subscriber B by the operation of relay 126 through equipment not shown but described inthe above mentioned copending application, and the release of the connection at the end of the conversation may be accomplished in any well known manner.

What is claimed is;

1. In a telephone system two telephone exchanges, subscribers lines terminating at one of said exchanges, a line composited for simultaneous telephony and telegraphy interconnecting said exchanges, automatic switching means at one of said exchanges for interconnecting said composited line with any one of said subscribers lines,

means atsaid other exchange including an of said exchanges, liae composi ed f terconnecting said exchanges,

composited line to control the operation of said switching'means, 'a signal at said other exchange, and means for operating said signal when the line has been seized and said switching means is ready to be controlled by said impulses to select the subscribers line.

. 3. In a telephone system an operators cord circuit, a composited line, an impulse circuit including'an impulse sender, means for connecting said impulse circuit to the cord circuit, means operated when the line is seized by said. cord circuit for connecting one leg of the composited line to the impulse circuit, a signal, means operated by the reversal of the current on the composited leg for interruptedly operating said signal, and means operated when the impulse sender is actuated to release said signal from the interrupting means.

4. In a telephone system a composited line, a cord circuit adapted to be connected thereto, an impulse circuit including a sender, means for completing said circuit to one leg of the composited line, a signal, and means for interruptedly operating said signal responsive to one polarity of current only on said line.

'5. In a telephone system a composited line, a cord circuit adapted to be connected thereto, an impulse circuit including a sender, means for completing said circuit to one leg of the composited line, asignal, means operated in response to one character of current on said line to cause the signal to be interrupteclly actuated and means for making said signal operating means ineffective when the impulse sender is operated.

6. In a telephone system a composited line, a cord circuit adapted to be connected thereto, an impulse circuit including a sender, means for completing said circuit to one leg of-the composited line, a signal, means operated in response to one character of current on said line, and means controlled by the operation and release of the impulse sender to cause said signal'to be steadily operated when the same character of current is present onthe line.

7-. In a telephone system I a composited line, a cord circuit adapted to be connected thereto and comprising a signal and means including a key Wh ch in operated posit on maintains said'signal operated under con-' trol of a current over the composited leg of said line, meaizs in said composited line for maintaining said signal operated under conafter said key has been signal when the current is removed from the line or reversed thereon.

9. In a telephone system a composited line, a cord circuit: adaptedto be connected thereto and comprising a signal and means including a key which in operated position maintains said signal operated under control of a current over the composited leg of said line, means in said composited line including a polarized relay operated by the same current on the composited leg of said line to maintain said signal operated when said key is released and when said relay is released on the ceasing of the current on the line to cause said signal to be entirely removed from control of any subsequent currents on the line. I j

10. In a telephone system a composited line, acord circuit adapted to be associated therewith, means including a common relay for disconnecting the line for telephonic purposesand for connecting a composited leg of said line for signaling purposes, a low frequency alternating current source, and means independentof said disconnecting and connecting means for applying current from said source to said composited leg, a signal, and means responsive to said current for operating said signal.

11. In a telephone system, a composited line, means for .disabling said line for telephonic purposes and for connecting a leg of the line for signaling purposes comprising a source of low. frequency alternating current, a source of direct'current, a relay and a key so arranged that the operation of the key causes the operation of the relay by current from the direct current source, the operation of the relay causes the disabling of the line for telephonic purposes and the connection of the said leg for signaling purposes while .the operation of the key and the relay causes the application of current from the alternating current source to the said leg for signalmg purposes. j

12. In a telephone system atwo conductor telephone line, an impulse sender, means for connecting said impulse sender to one conductor of saidline, an alternating current re lay, a signal normally under control of said relay and means operated by said connecting means forremoving said signal from the control of said alternating current relay.

13. In a telephone system a tWo conductor and means operated by said connecting telephone line, an impulse sender, means for means for disconnecting said relay from said 10 connecting said impulse sender to one conconductor. ductor of said line, an alternating current In testimony whereof, I have signed my relay normally connected to said conductor, name to this specification this 25th day of I an alternating current source, means for February 1924:. operating said relay by the application of currents from said source to said conductor, JOHN F. TOOMEY. 

